Okay, then show me where Mueller said there was collusion...because he didn't. I've checked AP's reporting, NPR, NBC. The closest thing came from Politico of all places and even that didn't say there was collusion, he just said it wasn't evaluated as they were looking for evidence to charge the Trump campaign with criminal conspiracy, which was none:
Show me where I said that they did? He said "collusion" wasn't evaluated because it isn't a legal term.
"In evaluating whether evidence about collective action of multiple individuals constituted a crime, we applied the framework of conspiracy law, not the concept of “collusion.” In so doing, the Office recognized that the word “collud[e]” was used in communications with the Acting Attorney General confirming certain aspects of the investigation’s scope and that the term has frequently been invoked in public reporting about the investigation. But collusion is not a specific offense or theory of liability found in the United States Code, nor is it a term of art in federal criminal law. For those reasons, the Office’s focus in analyzing questions of joint criminal liability was on conspiracy as defined in federal law."
His job was to look for "links and coordination". There was no expressed agreement between the Russian government and the Trump campaign so the was no "coordination" as Mueller defined it (also not a legal term).
"The order appointing the Special Counsel authorized him to investigate “the Russian government’s efforts to interfere in the 2016 presidential election,” including any links or coordination between the Russian government and individuals associated with the Trump Campaign."
Links though...they found links.
"As set forth in detail in this report, the Special Counsel’s investigation established that Russia interfered in the 2016 presidential election principally through two operations. First, a Russian entity carried out a social media campaign that favored presidential candidate Donald J.
Trump and disparaged presidential candidate Hillary Clinton. Second, a Russian intelligence service conducted computer-intrusion operations against entities, employees, and volunteers working on the Clinton Campaign and then released stolen documents. The investigation also
identified numerous links between the Russian government and the Trump Campaign. Although the investigation established that the Russian government perceived it would benefit from a Trump presidency and worked to secure that outcome, and that the Campaign expected it would benefit electorally from information stolen and released through Russian efforts, the investigation did not
establish that members of the Trump Campaign conspired or coordinated with the Russian government in its election interference activities."
Trump welcomed the help instead of reporting it to the FBI like a good American would have.